A Mississippi man arrested last week for allegedly sending ricin-tainted letters to President Obama was released today and the charges against him dismissed, as federal agents began searching the home of a new suspect this afternoon.

Paul Kevin Curtis was released this morning from federal custody and said today that he was "overwhelmed" by being arrested and charged with sending threatening letters to government officials. The charges were dismissed without prejudice, so that they could be reinstated if the investigation warranted it.

Curtis, 45, was arrested at his home in Corinth, Miss., a day after a letter laced with the poison was discovered addressed to Sen. Roger Wicker, R-Miss. A second letter was intercepted before it reached President Obama and a third letter was mailed to Sadie Holland, a justice of the peace in Lee County, Miss.

Officials said that the signature on the letters matched that of Curtis' online postings and other letters he had mailed. He consistently signed them "I am KC and I approve this message," according to an FBI affidavit.

During a bond hearing on Monday, however, FBI investigators admitted that there was no physical evidence that Curtis had sent ricin, a poison made from ground castor beans, to the officials. Curtis's attorney, Christi McCoy, called for his release.

McCoy and Curtis, an Elvis impersonator and enteratiner, appeared today in Oxford, Miss., to praise federal officials for dropping the charges and investigating other suspects in the crimes.

"We're just thrilled, so happy with the government," McCoy said. "Sometimes law enforcement will get on one angle and stay on that angle no matter what, and we are so happy that was not the case here. They went where the evidence led, realized it was a dead end, and went where true evidence was."

"I mean, let's be honest," McCoy said at the conference, "his Facebook page and writings directly correlated with what was sent to our officials. I haven't seen anything that makes me think they acted recklessly."

"It feels amazing, it feels wonderful," Curtis said. "It was overwhelming to say the least. The last seven days, staring at these four great walls, and to not know what's really happening, not having a clue when I'm there. I was just in a state of being overhwelmed."

Meanwhile, federal agents searched the home of Everett Dutschke, a Tupelo, Miss., resident currently facing charges for child molestation. Curtis said that Dutschke has had a long-running conflict with him.

Curtis was released this morning after the third day of his bond hearing was abruptly cancelled as lawyers met with prosecutors privately in the courthouse.

Niether McCoy nor the U.S. Attorney's office handling the case have responded to requests for comment.

Investigators testified on Monday that they found no trace of the poison or the tools they think could have created it in Curtis's home or car, and no Internet searches for how to make the drug on his computer.

FBI agent Brandon Grant believed that the ricin was made by crudely chopping castor beans in a food processor or blender, neither of which were located in Curtis's home, according to ABC News affiliate WTVA-TV.

Curtis' attorney, Christi McCoy, said there was no physical evidence tying her client to the alleged crime.

"There continues to be more and more evidence, or lack of evidence, that's being fleshed out," McCoy said Monday, according to WTVA.

"The big part that we took from the testimony is that thorough and complete searches were done of Mr. Curtis's residence, his former wife's residence, as well as his vehicle -- the vehicle he was driving at the time of the stop -- and there was nothing found on anything that linked him to these crimes."

Curtis told the court Monday that he would no longer use computers or Facebook and that he would no longer engage in activism, believing his activities online led to his arrest.

According to the criminal complaint lodged against him, the FBI quickly traced the tainted letters to Curtis's house by matching the signature on the letters, which read "This is KC and I approve this message," to a number of other letters and Internet postings Curtis had written.

The letter was mailed from Memphis, Tenn., about 100 miles north of Curtis's home, according to the charging documents.